package util;

import org.apache.commons.collections.MapUtils;

import java.text.DecimalFormat;

/**
 * Created by bowen on 2017-08-16.
 */
public class BaiduGeocoder {

    public static double computedDistance(double wd1, double jd1, double wd2, double jd2)throws Exception {
        DecimalFormat df = new DecimalFormat("######0.00");
        double x, y, out;
        double PI = 3.14159265;
        double R = 6.371229 * 1e6;
        x = (jd2 - jd1) * PI * R * Math.cos(((wd1 + wd2) / 2) * PI / 180) / 180;
        y = (wd2 - wd1) * PI * R / 180;
        out = Math.hypot(x, y);
        return Double.parseDouble(df.format(out));
    }

    private static double EARTH_RADIUS = 6371.393;
    private static double rad(double d)
    {
        return d * Math.PI / 180.0;
    }

    /**
     * 计算两个经纬度之间的距离
     * @param lat1
     * @param lng1
     * @param lat2
     * @param lng2
     * @return
     */
    public static double GetDistance(double lat1, double lng1, double lat2, double lng2)
    {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lng1) - rad(lng2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a/2),2) +
                Math.cos(radLat1)*Math.cos(radLat2)*Math.pow(Math.sin(b/2),2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 1000);
        return s;
    }



    @org.junit.Test
    public void test() throws Exception {
//        System.out.println(GetDistance(31.060518,121.53958,31.060565,121.540269));

        double r = GetDistance(121.539935,31.059809,31.060518,121.53958);
        System.out.print(r);
    }

}
